The victim, in his early 20s, was left with a severe, three-inch wound on his cheek which required ten external stitches and more inside.

Buck, of Middlewood Chase, Middlewood, was jailed after pleading guilty to possessing a knife and wounding with intent.

Gul Nawaz Hussain, for Buck, said: “He will miss the imminent birth of his first child and will miss the formative years of that child’s development, which often have the most cherished memories for any parent.”

The victim told the court in a statement that the incident had had a massive effect on his life.

He said: “My face is scarred for life and I have no feeling on that side of my face. The only feeling I get is an occasional ‘electric shock’ pain.

“I have these scars as a permanent reminder.

“I actually went for a job interview and the first question he asked was, ‘What’s that? How have you got that scar?’

“I’m going to have that kind of initial reaction from people forever.”

He has since been referred to mental health services due to slipping into a ‘terrible depression’.

His victim impact statement added: “Since the incident I have changed – I have grown up.

“I have learned that in these situations it’s best not even to start talking because you don’t know where it will lead.”

Ian West, prosecuting, said the victim was making his way home from work on July 25 last year when the pair got into an argument.

He said: “The complainant was saying, ‘What are you staring at?’ And the defendant responded, ‘What are you staring at?’.”

After a short exchange of words the victim started to walk away, but Buck mouthed an insult under his breath and then reached into his man bag.

The victim was concerned he had a knife.

Mr West said: “The complainant thought attack was the best form of defence so he went into his bag, pulled out a key, and hoped that by bluffing he had a knife it would deter the defendant. It didn’t.”

Buck lunged at the man with a small kitchen knife.

The victim was scared and opened his hand to show Buck he only had a key. He pushed him away but then Buck sliced his face with the knife.

Mr Hussain had told the court Buck has a form of autism meaning he cannot interpret certain social situations.